Present-day motor vehicle technology includes several different types of known driver assistance systems, such as Adaptive Cruise Control (ACC) systems that can autonomously or semi-autonomously control the acceleration and braking functions of a motor vehicle to follow a leading vehicle that travels ahead of the subject or ego vehicle. The typical behavior of such driver assistance systems includes a relatively small occurrence rate of erroneous reactions or omitted reactions to other traffic participants (such as other motor vehicles or pedestrians) or obstacles in the environment around the subject vehicle. With the increasing automation of the driving of motor vehicles, the proper detection and monitoring of other traffic participants, and avoiding the oversight or missing of such other traffic participants, are becoming especially more critical. Because the proper tuning or coordination of such systems involves a balancing between a reliable recognition (availability) and avoidance of erroneous reactions, this balanced tuning must favor the reliable recognition of objects especially in connection with automated or semi-automated driving in order to achieve greater safety and reliability. This, however, necessarily leads to an increased rate of erroneous reactions of the systems in borderline or marginal situations.
In present-day driver assistance systems, the monitoring and correction of erroneous reactions of the system is at least partially up to the human driver of the vehicle. For example, such systems allow the driver to override erroneous system reactions (for example an automated braking of the subject vehicle based on another vehicle that is driving ahead in a neighboring lane rather than the subject vehicle's own lane), by stepping on the gas pedal during the time of the erroneous system reaction (e.g. the erroneous automated braking). However, such “overpowering” of the automated or semi-automated control by the driver assistance system for the duration of the automated control occurrence is typically regarded as interfering and uncomfortable by the driver. Thus, it would be desirable to reduce such erroneous system reactions, or to simplify the driver's monitoring of the system reactions and/or to shorten the duration of the driver's overriding measures and/or to reduce the effort required of the driver's overriding measures.
A general method of the type mentioned above in the field of relevant art is known from the German Patent Publication DE 10 2008 002 576 A1, in which a sensor system locates objects and a driver assistance system calculates at least one plausibility measure (confidence value, reliability) on the basis of the location data thereof, for establishing the plausibility of the detected object data. Particularly, the plausibility value indicates the existence probability of the object and/or the probability of correct applicability of a particular object characteristic. In order to decide as to the existence of the object or the applicability of the object characteristic, a threshold value function is applied to the plausibility value. Thus, for example, all objects are regarded as real if their respective plausibility values lie above the threshold value of the threshold value function.
It has been found, however, that in this known method, erroneous system reactions of a driver assistance system are not avoided in all traffic situations, and therefore such erroneous system reactions must again be overpowered or overridden by the driver.
The German Patent Publication DE 100 48 102 A1 discloses a driver assistance system for supporting and relieving burden from a driver of a motor vehicle, in which the driver is included in the control in rarely occurring driving situations in the context of an ACC driver assistance system in traffic following operation, in that the relative target objects to be utilized for the speed regulation in the following operation are selected among the detected target objects dependent on their speed and dependent on the driver's manual operation of an operating element arranged in the vehicle. Particularly in this regard, target objects that are moving and classified as relevant target objects among the detected target objects are automatically used for the speed regulation, whereas stationary target objects are selected for the speed regulation only upon request by the vehicle driver, namely by the driver's operation of the operating element arranged in the vehicle. Thereby the system effectiveness of the driver assistance system shall be significantly improved and simultaneously the trust or confidence of the driver in the speed regulation all the way to a complete standstill of the vehicle is increased. However, erroneous system reactions cannot be avoided even in this known driver assistance system.
Furthermore, the German Patent Publication DE 10 2006 027 554 A1 discloses a vehicle with an ACC driver assistance system with which the speed of the vehicle is regulated and a motor or a braking system is activated dependent on a desired nominal value of acceleration. In such an ACC driver assistance system, the maximum achievable positive and negative acceleration values are limited. These limits can only be released or exceeded by an overriding by means of the driver's operation of the driving pedal (e.g. accelerator pedal) or the brake pedal, whereby however the driver assistance system is deactivated and thereafter must again be switched on. This is regarded as inconvenient and disadvantageous.
In order to give the driver of the vehicle a comfortable and simply operable possibility for correcting erroneous or interfering driving behaviors of the driver assistance system, this German Patent Publication DE 10 2006 027 554 A1 proposes to provide for the driver an operating element that communicates with the driver assistance system. Upon the driver's actuation of the operating element, at least one signal is produced, so that during the operation of the operating element, the driver assistance system changes the desired nominal acceleration value dependent on the signal produced by the operation of the operating element, and the motor and/or the brake system of the vehicle is actuated dependent on the changed desired nominal acceleration value.
Thereby a comfortably operable driver assistance system is presumably achieved, but even this known driver assistance system has the disadvantage, that upon the occurrence of erroneous system reactions the vehicle driver must still override such system reactions. Thereby, of course, the availability of such a driver assistance system is disadvantageously reduced.